PHP: single-line attributes are highlighted as one flat token, unlike multi-line ones

[kix]

Summary

In the PHP lexer, a single-line PHP 8 attribute is emitted as one flat Name::Attribute token, while the same attribute split over several lines is tokenised normally (strings, names, punctuation, etc.). The two forms therefore render very differently, e.g. in GitLab diffs and file views (GitLab uses Rouge).

Follow-up to #1759, which added attribute support.

Cause

lib/rouge/lexers/php.rb, :php state:

rule %r/#\[.*\]$/, Name::Attribute

This matches #[ ... ] to the end of the line as a single token. Multi-line attributes do not match (no ] at the end of the first line), so they fall through to the generic rules and get proper highlighting.

Reproduction

<?php

class FooController
{
    // Rendered as a single flat Name::Attribute token:
    #[Route(path: '/crews/members/remove', name: 'crews_members_remove')]
    public function remove(): Response {}

    // Rendered with normal tokens (strings, keywords, punctuation):
    #[Route(
        path: '/crews/{crew_id}/members/{user_id}',
        name: 'crews_members_details',
        requirements: ['crew_id' => '\d+'],
    )]
    public function details(): Response {}
}

Expected

Both forms highlight the same way: #[ and ] as attribute punctuation, the attribute class as Name::Attribute (or Name::Decorator), and the arguments tokenised as ordinary PHP (named-argument labels, strings, arrays, constants).

Possible fix

Replace the single-line rule with one that pushes an :attribute state on #[ and pops on the matching ], tracking bracket depth, so that the contents are lexed as PHP regardless of line count.